Molecular breeding technologies and strategies for rust resistance in wheat (Triticum aestivum) for sustained food security

Abstract

Wheat is an important cereal food crop providing key nutrients to humankind. Rusts are the most destructive pathogens of cereal crops, with the exception of rice, across the world and resistant cultivars have been widely employed to reduce the yield losses caused by them. The modern intensive monoculture of cultivars and changing climatic conditions has created congenial conditions for the emergence of new virulent races such as Ug99, which is a great concern for world food security. Conventional breeding efforts have not been effective in quickly developing new varieties with durable and broad‐spectrum resistance against the rapidly evolving rust pathogen races. However, in the last two decades, biotechnological methods such as marker‐assisted selection (MAS) and transgenic technology have provided novel strategies for enhancing resistance levels and durability in crop plants in a short span of time. Nevertheless, broad application of transgenics in agriculture is hindered by biosafety apprehensions. In recent years, improved versions of biotechnological breeding methods such as genomic selection, genome editing technologies, cisgenesis and intragenesis, RNA‐dependent DNA methylation (RdDM), agroinfiltration and reverse breeding are gaining popularity. These technologies provide a tremendous capability to manipulate crop plants more precisely than before and accelerate crop improvement efforts for sustained food production as well as overcoming safety concerns associated with food crops.

Introgression of Two Quantitative Trait Loci for Stripe Rust Resistance into Three Chinese Wheat Cultivars

“…Studies focused on Xiangmai 25 and Zhengmai 9023 have not identified genes for stripe rust resistance; however, they are presumed to contain unknown resistance genes based on field resistance evaluation ( Figure 4A). Combining these unknown resistance genes with the two QTL from P9897 can provide a long-lasting and high-level resistance to stripe rust [2]. For example, Xiangmai 25/P9897-34 has a higher resistance (IT = 0, DS = 0%) than the donor parents P9897 (IT = 2, DS = 10%), so we speculate that this line combines the unknown resistance genes from Xiangmai 25 with the two QTL from P9897.…”

“…It is planted in over 200 million hectares per year with a production of 751.1 million tons, and human consumption of wheat is increasing every year [1]. By 2050, the global population will exceed 9.5 billion, according to the World Bank, and global wheat production needs to increase by 60% to meet food demand [2,3]. Wheat stripe rust is caused by Puccinia striiformis f. sp.…”

Review on Plant Diseases Management Through Gene Pyramiding

“…Although, these genes are ineffective individually to the upcoming pathotypes of stem rust in India and elsewhere in the world, pyramided lines are expected to provide durable resistance against all the races. Agronomic performance of the improved lines was compared with the recipient parent [26].…”

Breeding Low-Cadmium Wheat: Progress and Perspectives

“…However, the tolerance established in crops with conventional methods is usually not very robust or broad-spectrum [74]. Conventional selections are dependent upon several environmental variations and thus require a widespread location/generation field trial, delaying the progress of cultivar development [75]. As a general breeding criterion, 8-10 years of substantial breeding efforts are required to breed a cultivar right from the pre-breeding phase up to commercial release [76].…”